This application relates to the art of assembly apparatus and, more particularly, to apparatus for assembling plate and tube-type of heat exchangers. However, it will be recognized that many features of the apparatus constructed in accordance with the present application can be used in other types of assembly apparatus.
Heat exchangers of a known type include a plurality of spaced-apart parallel tubes having opposite end portions extending through holes in end plates and being joined to such end plates. One or more intermediate plates may be provided for holding the tubes in parallel spaced-apart relationship but without the tubes being permanently joined to such intermediate plates.
Prior to joining of the tube end portions to the end plates, a number of preliminary work steps are necessary, such as positioning, milling and expanding. The tube end portions are then welded to the end plates and the pipe end portions are rolled into the end plate. Apparatus required for the welding and rolling operations is known to those skilled in the art. However, joining of the tube end portions to the end plates is primarily carried out manually and this is very expensive when considering that heat exchangers commonly have hundreds of tubes.
Heat exchangers of the type described can be around ten meters in length and it has been believed that an automatic assembly machine for joining both end portions of the tubes to the end plates would have to be of enormous size. Also, an apparatus with a pair of spaced-apart work stations at a fixed distance from one another would be impractical because heat exchangers of the type described are manufactured to a great variety of lengths.
It would be desirable to have an economical apparatus for use in joining tube end portions to end plates in the manufacture of tube and plate heat exchangers.